Apparatus for removing pulp laps or webs



Newn 23 9 1926.

C. M. M ALLISTER APPARATUS FOR REMOVING PULP LAPS OR WEBS Filed May 23, 1925 4 Sheets-Sheet 1 C'arence Murray Macmisfer Nbv. 23,1926. 1,608,129

C. M. M ALLISTER APPARATUS FOR REMOVING PULP LAPS 0n WEBS Filed May 23, 925 .4 Sheets-sheet 2 Cimence Murray Macmisfer InvenYor y r I Afforngys NW. 2s 1926. 1,608,129

C. M. M ALLISTER APPARATUS FOR REMOVING PULP LAPS OR WEBS Filed May 23, 1925 4 Shoots-Shoat 3- Clarence Murray Macmhsfer InveMor.

Nov. 23 1926.. I 1,608,129

C, M. M ALLISTER APPARATUS FOR REMOVING PULP LAPS OR W555 Filed May 23, 1925 4 Shuts-Shoat 4 l I Clarence Murray )llaclliefer InvenYor.

Arfomeya Patented Nov. 23, 1926.

insane CLARENCE HUB-FAY MACALLISTEB, OF I-ZABVIEESBU OHTAEIG, CANADA..

' APPARATUS FOR REMOVING PULP Application filed May 23, 1925, Serial No. 32,420, and

T he present invention relates to apparatus for removing laps or webs of pulp from the surface on which they are formed, and more especially to apparatus for removing laps or webs of sulphide pulp from the top pressroll of a wet machine.

The removal of sulphioe pulp laps from the press roll presents diriiculties which to the best of applicants knowledge have never been overcome by any of the devices hitherto proposed for the purpose. The pulp is tough and difficult to sever, and, as the cutting is to he performed without stopping -ae machine, the cutting has to be accomplished v ry quickly, and consequently, if the apparatus does not operate with smoothness and certainty there is danger of breakof the mechanism.

This invention has for its object to provide an apparatus which overcomes the difficulties above mentioned and according to the present invention two cutting means may be provided normally positioned at each side of the surface from which the pulp is 7 to be removed, and means is provided for causing movement of the cutting means to wards each other to sever the pulp when the desired thickness of pulp has been formed on the surface. \(lechanism is also provided for advancing the cutting means, during their actuation, at the same or substantially the same speed surface from which the lap is to be removed.

Gther features of the invention will become apparent from the subsequent description and from the appended claims.

One convenient embodiment of the invention is illustrated by way of example in the accompanying drawings, in which Figure. 1. is substantially a plan of the improved machine with the arms and parts carried thereby being viewed at right an 'le to the longitudinal axis of the arms as seen in Figure 2, certain parts being in section.

Figure 2 is aside elevation, I

Figure 3 is a front elevation with the cylinders shown in section,

Figure 1 is an enlarged view of means for causing the movement of the cutting mechanism,

Figure 5 is an enlarged section of a portion of a cylinder,

Figure 6 is a side elevation of means for securing the cylinders in position,

as that of the' are on wars.

de. May is, 1925.

Figure 7 is a side elevation illustrating modihed means 101' advancing the cutters during the cutting operation.

1n the drawings parts shown in certain figures are omitted or broken away in certain other figures'to expose parts which would otherwise be hidden.

The main parts of the machine to which the invention is shown applied comprise a top press-roll 1 and a bottom roll 2 sup-. ported'in bearings 3 and 1 respectively, carried by frames 5. A felt 6 passes around the roll 2' and conveys pulp to the machine which is picked up by the roll 1. The pulp accumulates onthe surface of the roll 1 until a lap of the desired thickness has been built up and the lap has then to be cut, and removed from the roll 1 to permit another lap to be formed.

The mechanism for supporting the cutters and cutter-actuating means comprises a suit able frame pivoted on the shaft of the top roll 1, and is illustrated as consisting of. a beam 7 of I-section connected at each end to an arm 8 mounted at its inner end on the spindle of the top roll 1. The beam 7 is rigidly connected to the arms 8 as by means of blocks 9 which have machined recesses 10 adapted to slide in a machined slot 11 in standard 12, the centre of curvature of this slot being coincident with the centre of the top roll 1.

Arranged parallel to the beam 7 is a bar 13 which is rigidly supported at both ends by brackets 14 riveted or bolted to the beam 7 Cross-heads 15 are mounted to slide on the bar 13 and roller hearings or other ant friction devices, not shown, may be provided in the cross-heads if desired. Lugs 16 extend from the cross-heads 15 towards the top roll 1, and to these lugs cutters 17 are pivoted at 18. The cutters are pointed at their inner ends and have cutting edges 19, and

means, such as springs 20, are provided to give the pointed ends of the cutters a tendency to press towards the surface of the top roll 1. r

The cross-head of the right hand cutter is provided with a lug 21 which is connected to a piston 22 in a cylinder 23 by means of a connecting rod 24. The cross-head'of the left hand cutter has a lug 25 connected to a piston 26 in a cylinder 27 by means of a connecting rod 28.

The means for controlling the admission and exhaust of presure fluid such as steam or air, to and from the cylinders 23 and 27., may comprise a valve cylinder 29 in which slide the valve pistons 30 and 31 mounted on a rod 32 rigidly connected by a bar 33 to a rod 3& projecting through a stutiing box for short distance into the cylinder 27. The rod is extended outwardly beyond to bar 33, as shown at 34', and is ot fset towards the roll 2 and is preferably provided with a roller 35. The roller 35 contacts with a cam plate 36 pivoted at 37 on a fixed standard 33 to move the valve pistons 30 and 31 in one direction as will be described hereinafter. The cam 36 is normally held in its upper position against a stop 39 by a spring 10 connected to the standard 38 and the cam. The standard is omitted from Figure 2. The cylinders 23, 27 and 29 are clamped together and secured to the beam 7 by any suitable means as indicated at 1 0 in Figures 2 and 6.

Means are provided for swinging the arms 8 and parts carried thereby in an upward direction when the desired thickness of pulp has accumulated on the roll 1. The cutters are actuated during the ascent of the arms 3 and since. according to this form of the invention, the arms are raised by the roll 1, the cutters are advanced in the direction of travel of the roll surface at the same speed as the periphery of the roll 1. and consequently a straight out made across the lap parallel to the axis of the roll 1.

The means for actuating the cutter-raising means may be as follows: On the inner sur face of one of the arms 3 is provided a pocket 41 in which is slid-ably mounted a latch 42 constantly urged outwardly by aspring 43 but normally held in retracted position by a bolt i l passing through a hole in the pocket and engaging a recess in the latch.

The latch is released by any suitable means when the pulp has attained the predetermined thickness. the means illustrates for effecting such release comprising a solenoid winding 45 surrounding the outer end of bolt 44-. One end 01" this winding is connected through a flexible or other suitable conductor 46 with one pole or a source of current 47. The other end or" the winding is joined by conductor 43 to a bracket e9 on arm 8 or direct to arm 8. The other pole of the source of current a? is joined by a conductor 50 to a spring contact 51 which is mounted on, but insulated from. the bracket 3. An insulated projection 52 on the lower side of the spring 51 contacts with the bearing block 53 resting on the shaft of roll 1. A vertically adjustable contact 54 is carried by the bracket 49.

If desired. a mechanical connection may be provided instead of the electrical connection for withdrawing the bolt 44:.

The operation or" the apparatus is as follows: As the pulp accumulates on the roll 1 the roll rises and carries with it the block 53 and the latter through projection 52, causes the spring 51 to be b-ent upwardly. The contact 54 on the arm 3 also rises but owing to the force being applied to the spring 51 near its fulcrum, the contact point on spring 51 overtakes t le contact 5%. contact 51 touches it at the moment the desired thickness 01 pulp has been obtained. The closure of contacts 51 and 5% completes the circuit through the solenoid winding 45 and the winding being thus energiZe-d causes the bolt id to be withdrawn from the recess in the latch 1 against the action of a spring 55 which may be provided desired. The compressed spring 43 then pushes the latch 12 into its outer position in which the outer endot the latch lies in the path of travel or" a dog 56 which is suitably secured to the end of roll 1.

VVhen the do en -ages the latch 42 the a a a 7 arms 3 and parts carrwd thereby are caused to swing upwardly the same angular speed as the roll 1. As this upward motion starts the roller 35 rides along the inclined face 35 the cam and thus causes the rods 32 and 34 to be thrust into the left hand position as viewed in F igure 3 thus bringing valves 30 and 31 into the positions indicated in chain-dotted lines; A suitable fluid, such as steam or air under pressure is constantly ted to the valve cylinder 29 through a conduit 5! which has sutiicientflexibility or is otherwise arranged to allow for the in ven'ieut ot' the valve cylinder. i i/ hen the valves have been moved into the dotted position, the fluid flows from inlet pipe 5'? into the space between the two valves and then by way of pipe 58 to cylin= ders 23 and 27 the fluid entering the cylinders through one-way valves 59. The piston 22'is therefore moved quickly to the left hand end or its cylinder 23 and piston 26 to the right hand end of cylinder 27 and consequently the cutters 1?, through the connecting and cross-heads 15 are moved towards the middle of the surface of the roll 1, the stroke of the pistons 22 The contact 54 is so adjusted that the and 26 being such that the cutters approach 7 each other closely as possible without actually touching. The cutters move under the pulp and the cutting edges 19 sever the pulp. and since the cutters are moving in the direction of travel at the roll sur 'ace and the same speed the surface of the roll a straight out is roduced.

During this outward stroke 013 the piss tons 22 and the previous'charges of fluid in cylinders 23 and 2.7 are exhausted to atmosphere through conduits 60 right hand end of cylinder 29 and port- 61-.

During the last portion of its outward stroke the piston 26 moves the rod 34 outwardly and, through bar 33, causes the valve rod 32 to be moved to the right to bring the valves and 31 into the position shown in full lines in F igure 3. Fluid now passes from pipe 57 to the inter-valve space and thence by way of pipes 60 to the outer ends'of cylinders 23- and 27, thus torcing pistons 22 and 26 to their inner posi tion and returning the cutters 17 to their normal outer position. During this stroke the previous charges of fluid are'exhausted to atmosphere through one-way valves 62, pipes 58, left-hand end of valve cylinder 29 and port 63 After the pistons 22 and 26- h-a-ve covered the branch pipes "from the exhaust valves 62, the air in front of the pistons is compressed by reason or" thevalves 59 being closed, and this compression absorbs shock. associated parts willremain in this position until another pulp lap has been formed.

The pressure of the fluid is so adjusted that the speed of the cutters towards each other is such that the cutters complete their cutting strokebefore the arms 8 havereached the upper end of their movement.

A bufier device 64 may be provided to coact with blocks 9 and thus absorb shock when the arms 8 reach their uppermost position indicated in chain-dotted lines in Figure 1. As the arms 8 approach near to their upper position the outer end of latch 42' engagesa stationary cam surface 65 which causes the latch to be thrust back into the pocket 41 against the action of spring 43. The contact between parts 52' and 54 is at this time broken, and consequently the bolt 44 falls into hole in latch 42 as soon as the hole comes beneath the bolt, and the latch is therefore held in retracted position. The arms 8 and parts carried thereby then fall towards their normal position and as this position is approached roller 35 passes the cam plate 36 by rotating this plate against the action of spring 40 which is strong enough only to lift the plate against stop 39 when the extension rod 34 has passed the plate, but is notstrong enough to shift the valve rod during the passage of the rod 34 in a down ward direction.

The last portion of the downward movement of the arms 8 and parts carried by it is slowed down by any suitable device, for example, one or more dashpots, one of which is illustrated as comprising a plunger 66 carried by the beam 7 and a cylinder 67 secured to the bed of the machine. These are provided to avoid shock and also to ensure that the severed lap of pulp has passed out from between the rolls 1 and 2 by the time the arms 8 reach their lowermost position. By the time this position of the arms is reached the contact 54 has returned to its 7 The pistons 30 and 31 and normal position above contact 51, but the has been removed and the roll 1 and its bearing block 53 has-therefore descended to its normal position.

Instead of coupling the arms S'direCt to the roll 1 to accomplish the upward movement of the cutters, such upward movement may be etiected by means independent of the roll, for example as illustrated in Figure 7. In this modificationthe arms 8, or one of them, is pivotally connected to a rod 68 to the lower end of which is attacheda piston 69 slidable in a cylinder 70 pivotally mounted asat 71 to the frame of the machine. Fluid under pressure is supplied to the cylinder by a. flexible pipe 72 through an adjustable valve 73 and a valve 74 slidable in a casing 75. Normally the port 76 is connected toatmosphere through a'passage 7? in the valve 74. Vi hen the contacts 51 and 54touch each other upon the desired thickness of pulp being formed, a solenoid 78 is momentarily energized and this raises a core 79 which, through a rod 80, raises the valve 74 to bring a passage 81 in the valve to connect the port 76 with the supply pipe 72. This action admits fluid to the cylinder and causes the piston to rise to the. position shown in dotted lines and also depresses a sliding rod 82 connected to rod by centrally pivoted link 83-. A port 84 relieves the pressure above the piston until it is cove-red by the piston. During the last part of the upward stroke the piston raises the rod 82 and thus depresses rod 80 and the valve 74 to cut 0d the fluid supply and exhaust the cylinder through passage 7'? to atmosphere. By adjusting the admission of fluid by means of valve 7 3 the speed of the piston can be so controlled that the arms 8 are raised to advance the cutters at the same or substantially the same speed as the periphery of the roll 1.

' The small length of pulp at the middle of the'lap which is not cut on account of the fact that the cutters cannot actually touch each other is torn through by reason of the fact that the cutters, in falling with the arms 8, arrest the leading edge of the lap and detach it from the roll surface.

The cutters may be made so that each is slightly out of the plane of the other so that they may overlap slightly at the end of their inward stroke. Or they may be both arranged in the same plane and the point of the one'may be recessed to receive the point of the other, so that they may overlap without touching.

It will be understood that the form of the invention described is given by way of example only and any modifications falling with in the scope of the appended claims may be made. shown provided with a pocket 41 and asso- For example only, one arm 8 is contacts are separated because the pulp lap ciated parts but the other arm may be provided with a similar equipment if desired.

hat I claim is 1. Apparatus for removing pulp laps or webs from the moving surface on which they are formed comprising two cutting devices normally disposed one at each side of said moving surface, means adapted to move said cutters towards each other to sever the pulp, means influenced by the thickness of the pulp andadapted automatically to cause said cutter-moving means to operate when a predetermined thickness of pulp has accumulated on the surface, and mechanism for advancing the cutting means, during the actuation thereof, at substantially the same speed as that of the surface from which the lap is to be removed, so that during the cutting operation there is substantially no relative movement between said surface nd cutting means in the direction of movement of said surface.

2. Apparatus for removing pulp laps from a rotating roll on which they are formed, comprising a cutting means, a support for said cutting means, means whereby the support is carried by the roll as if it were an integral part thereof wh n the lap reaches a predetermined thickness, mechanism for then moving said cutting means along the surface of the roll to cut the lap and means for releasing the support from the roll to permit the support to return to its normal position after the cutting operation, said cutting means comprising two cutters normally position-ed respectively at each end of the roll and means being provided to move the cut t-ei's along the surface of the roll to cut the lap from its edges to points adjacent its centre line.

3. Apparatus as claimed in claim 2, wherein the support comprises a pair of parallel arms one at each end of the roll and rotatably mounted concentric with the roll, a rigid member connecting the free ends of the arms, a guide bar parallel to said rigid member and crossheads mounted to slide on said bar, the cutting means being mounted on said, cross-heads and also connected to the mechanism for moving the cutting means along the surface of the roll.

4. Apparatus for removing pulp laps from a rotating roll on which they are formed, comprising a pair of parallel arms one at each end of the roll and rotatably mounted concentric with the roll, a rigid member connecting outer ends of said arms, a guide bar carried between the arms and parallel to said bar, cutters mounted on said crossheads, two cylinders carried between the arms, pistons in said cylinders, rods connecting each piston with one of the cross-heads, a spring pressed latch on at least one of the arms, a bolt normally holding said latch in retracted position, a dog on the end of the roll, means for withdrawing the bolt to release the latch into the path of said dog, means for admitting pressure fluidint-o the'cylinders to cause the cutters to perform their cutting strolre after the latch has been released, means for retracting the latch when the cutting stroke has been completed and means for then admitting pressure fluid to the other side of thepistons to cause the cutters to be returned to normal position.

5. Apparatus claimed in claim a, where: in the admission and exhaust of fluid to and from the cylinders is controlled by means comprising a valve cylinder, two spaced valve pistons in said cylinder, pipes leading from ports in the valve cylinder to ports in the main cylinders, a rod carrying said valves, a cam surface adapted to move said rod to place the valves to admit fluid for the cutting stroke, and a rod extending into the outer end one of the main cylinders and rigidly connected to the valve rod.

(3. Apparatus as claimed in claim l, where in the rigid member is composite member comprising bearing blocks slidingly disposed in arcuate slots substantially concentric with the roll, said slots-being formed in standards provided to support the arms laterally and guide them in their vertical movement. i

7. Apparatus for removing pulp laps or webs from the surface on which they are formed comprising two cutters, a normally stationary support for said cutters, mechanism for moving the support, when the desired thickness of pulp is reached, at such a speed that there is substantially no relative movement between said cutters and surface in the direction of movement of the latter,

and mechanism for actuating the cutting means to cut the pulp during said movement of the support, said means for moving the support comprising a rod pivotally connected to said support, a piston'on said rod, a cylinder in which said piston can reciprocate, a valve for admitting and exhausting fluid under pressure to and from said cylinder, means for controlling the speed of said piston, means influenced by the thickness of the pulp to operate said valve to admit fluid to the cylinder when the desired thickness of pulp has been formed and means to actuate the valve to exhaust the cylinder after the cutting operation.

ture.

(ILARENCE MURRAY MacALLlSTEl-l.

In testimony whereof I aiiix my signa-r 

